US Patent 11063071 Multilevel semiconductor device and structure with waveguides

A multi-level semiconductor device, the device including: a first level including integrated circuits; a second level including a structure designed to conduct electromagnetic waves in a confined manner, where the second level is disposed above the first level, where the first level includes crystalline silicon, where the second level includes crystalline silicon; and an oxide layer disposed between the first level and the second level, where the second level is bonded to the oxide layer, and where the bonded includes oxide to oxide bonds.